Diamond cut

ABSTRACT

A new method of cutting a gemstone such as a diamond, known as the “Galush” cut, is provided. According to an embodiment of the invention, the “Galush” cut gemstone has a crown portion, a pavilion portion and a girdle portion provided between the crown portion and pavilion portion. The crown portion includes an upper surface having a shape configured by first, second and third boundaries, which form a perimeter around the crown of the gemstone. Each of the first and second boundaries has first and second ends, and the third boundary is arc-shaped having first and second edges. The first and second edges of the arc-shaped boundary adjoin the first end of each of the first and second boundaries and the second end of each of the first and second boundaries meet at a common tip.

FIELD OF THE INVENTION

The present invention relates to a new cut and structure for gem stonessuch as diamonds.

BACKGROUND OF THE INVENTION

The value of a diamond is determined by several parameters includingclarity, weight, shape, color, and polish. The cut of the gemstone isgenerally chosen to maximize the fire of the diamond.

However, in order to produce a brilliant cut diamond having goodreflection and refraction (light dispersion), a relative large amount ofthe diamond raw material is wasted. Currently, 50%-80% of a diamond iswasted during the cutting process. Thus in order to obtain a one caratstone, it is not unusual for the diamond cutter to start with a roughstone weighing 1.7 carat, for example. Since the price per caratincreases exponentially in proportion to the carat weight, it is highlydesirable to reduce the waste and increase the yield from a rough stone.

Yields may be increased during the faceting process by expert cuttingwhich attempts to achieve a high quality light dispersion whileretaining more of the rough stone. Previously, the traditional practicewas to limit the angle of the base facets to less than 43% to obtain anacceptable reflection and refraction, which limited the potential savingand the consequent increase in yield.

Various attempts have been made to increase the diamond yield, such asutilizing a greater table spread (the ratio of the table diameter to thegirdle diameter). However, the quality and fire of the stone suffered.Other attempts include a mixed-cut square gemstone having a two-stepcrown, a girdle, and a pavilion (U.S. Pat. No. 5,970,744 to Greeff) anda diamond having a pavilion formed of seventy-two facets and a total ofone hundred and six overall (U.S. Pat. Nos. 3,286,486 and 3,585,764 toHuisman et al). However, since many of the facets are added after thebottom pavilion facets have already been cut, there is in fact noimprovement in yield.

SUMMARY OF THE INVENTION

The present invention provides a new way of cutting gemstones anddiamonds, which provides diamonds with a brilliance comparable with andeven greater than conventional or hybrid diamonds and which produce abetter yield than conventional cut diamonds. The new cut known as the“Galush” cuts provides an improved yield of approximately 30% comparedwith conventional diamond cuts. The “Galush” cut is applicable todiamonds and other stones especially round stones.

There is thus provided, according to an embodiment of the invention, agemstone having a crown portion, a pavilion portion and a girdle portionprovided between the crown portion and pavilion portion. The crownportion includes an upper surface having a shape configured by first,second and third boundaries, which form a perimeter around the crown ofthe gemstone. Each of the first and second boundaries has first andsecond ends, and the third boundary is arc-shaped having first andsecond edges. The first and second edges of the arc-shaped boundaryadjoin the first end of each of the first and second boundaries and thesecond end of each of the first and second boundaries meet at a commontip.

Furthermore, according to an embodiment of the invention, the crownportion further includes a plurality of facets formed from a pluralityof edges, each edge adjoining two other edges around the perimeter. Thenumber of edges may be an odd number. The number of edges may be aminimum of five edges.

Furthermore, according to an embodiment of the invention, the pluralityof facets may include substantially rhomboidal facets.

Furthermore, according to an embodiment of the invention, the crownportion further may include a plurality of secondary star facets.

Additionally, according to an embodiment of the invention, the pavilionportion may include a plurality of facets formed from a plurality ofedges, each edge having a common end. The number of edges may be an oddnumber. The number of edges may be a minimum of five edges.

Furthermore, according to an embodiment of the invention, the whereinthe plurality of facets may form a substantially 5-pointed star shape ora substantially 7-pointed star shape.

Furthermore, according to an embodiment of the invention, the pavilionportion may include substantially rhomboidal facets.

Furthermore, according to an embodiment of the invention, the pavilionportion further may include a culet base and a plurality of facetsextending from the culet base to the girdle portion. The plurality ofstar facets may form a substantially four-pointed star shape.Alternatively, the plurality of facets may form a substantiallytriangular shape.

In addition, there is also provided, according to an embodiment of theinvention, a method for cutting a gemstone. The gemstone may include acrown portion, a pavilion portion and a girdle portion provided betweenthe crown portion and pavilion portion. The method may include the stepof:

-   -   configuring the perimeter of the crown of the gemstone in a        shape having first, second and third boundaries, each of the        first and second boundaries having a first and second ends, and        the third boundary being arc-shaped having and having first and        second edges.

The first and second edges of the arc-shaped boundary adjoin the firstend of each of the first and second boundaries and the second end ofeach of the first and second boundaries meet at a common tip, the first,second and third boundaries forming the perimeter.

Furthermore, according to an embodiment of the invention, the method mayfurther include the steps of:

-   -   forming a first plurality of edges on the crown of the gemstone,        each of the first plurality of edges adjoining two other of the        first plurality of edges; and    -   forming a second plurality of edges on the pavilion of the        gemstone, each of the second plurality of edges adjoining two        other of the second plurality of edges.

Furthermore, according to an embodiment of the invention, the firstplurality of edges may include an odd number of edges. The number ofedges may be an odd number. The number of edges may be a minimum of fiveedges.

Furthermore, according to an embodiment of the invention, the method mayfurther comprise the step of forming a plurality of facets cut from thefirst plurality of edges.

Furthermore, according to an embodiment of the invention, the method mayfurther comprise the step of forming a plurality of secondary starfacets.

Furthermore, according to an embodiment of the invention, the method mayfurther comprise the step of forming a plurality of facets cut from thesecond plurality of edges, wherein each edge has a common end. Theplurality of facets may form a substantially 5-pointed or 7-pointed starshape.

Furthermore, according to an embodiment of the invention, the pluralityof facets may include substantially rhomboidal facets.

Furthermore, according to an embodiment of the invention, the pavilionportion further may include a culet base and the method may furtherinclude the step of forming a plurality of facets extending from theculet base to the girdle portion. The plurality of star facets may forma substantially four-pointed star shape or alternatively a substantiallytriangular shape.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding, the invention will now be described, by wayof example only, with reference to the accompanying drawings in whichlike numerals designate like components throughout the application, andin which:

FIGS. 1A-1F are schematic illustrations, showing the “Galush” cut of around diamond according to an embodiment of the invention in variousstages of cutting;

FIGS. 2A-2F are schematic illustrations, showing the “Galush” cut of around diamond according to a further embodiment of the invention invarious stages of cutting;

FIGS. 3A-3B illustrate a further embodiment of the “Galush” cut diamondaccording to the invention;

FIG. 4 illustrates a further embodiment of the “Galush” cut diamondaccording to the invention; and

FIGS. 5A-5C illustrates a further embodiment of the “Galush” cut diamondaccording to the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to a new method of cutting a gemstonewhich increases the yield while achieving a achieving a brilliance andhaving light dispersion.

The accepted theory in the gem industry that the optimal angle of thebase facets is roughly 41 degrees and that even small deviations fromthis figure will affect the brilliance of the stone has unduly limitedthe development of other methods of cutting stones. As described in theinventor's U.S. patent application Ser. No. 10/919,257, cutting the basewith fewer pavilions leads to a substantially increase in the yield.Thus, for example, a one carat brilliant cut stone may be produced froma rough stone weighing approximately 1.3-1.4 carat, compared withstandard cuts which use a rough stone weighing approximately 1.7 to 2carats to achieve a one carat stone. As will be appreciated such animprovement in yield (of approximately 30%) is especially significant inthe diamond industry, where stones are relatively very expensive.

The inventor has also realized that improvement in yield can be gainedby cutting and shaping the stone in a specific manner which alsoemphasizes the diamond's brilliance. The new cut of the diamond,hereinafter referred to as the “Galush” cut, achieves a greater yield byshaping the stone in a specific. It will be appreciated by personsknowledgeable in the art that though the examples refer to rounddiamonds the same principles also apply to other shapes and othergemstones.

The present invention is described, by way of example only, to FIGS.1-5, which illustrate different embodiments of the invention.

Reference is now made to FIGS. 1A-1F, which illustrate the cutting of around diamond, generally designated 10, using the inventive “Galush” cutfor a diamond, according to an embodiment of the invention. The “Galush”cut diamond has an innovative shape which appears to resemble a “sector”of a circle having a tip 2 at one end and an arc at its crown 4. The useof an arc 4 in the “Galush” cut provides an improved yield especiallywhen formed from conventional rough diamonds.

In a first step (FIG. 1A), five edges 12 a-12 e are cut on the crown 4of the diamond. In the next stage (FIG. 1B), five edges 14 a-14 e arecut on the base and a girdle is formed. The five edges 14 a-14 e mayhave a common end 15. FIG. 1C illustrates a composite view of the stoneshowing both the top edges 12 a-12 e and the bottom edges 14 a-14 e.

In he following stages illustrated in FIGS. 1D and 1E, the stone is“brilliantized”, that is facets are added. FIG. 1D illustrates theaddition of facets 20 and half facets 22 to the crown 4. FIG. 1Eillustrates the addition of facets 16, 18 to the base of the stone.Facets 16 may form a substantially 5-pointed star shape, as shown.

The completed stone is shown in FIG. 1F. As will be appreciated bypersons knowledgeable in the art, there are various embodiments,comprising a plurality of different combinations of facets and halffacets which may be added to a stone.

The main feature of the “Galush” cut diamond is the shape of thefinished stone and its brilliance. In prior art diamond cutting, a stoneis traditionally cut with an even number of facets, usually a multipleof 4. Thus, the crown of the brilliant-cut traditional diamond may have16 upper Girdle facets, 8 Star facets and 8 Bezel facets, for example.In contrast to the prior art, the inventive “Galush” cut diamond maycomprise an odd number of facets, as illustrated in FIGS. 1A-1F.

As will be appreciated, any number and type of facets may be added tothe stone without detracting from the novelty of the “Galush” cut.Reference is now made to FIGS. 2A-2F, which illustrate the cutting of around diamond, generally designated 50, using the inventive “Galush”cut, according to a further embodiment of the invention.

In the embodiment of FIGS. 2A-2E, the stone has the “Galush” shape, thatis having a tip at one end and an arc at its crown, and is cut accordingto the “Galush” method. In this embodiment, the “Galush” cut diamondalso comprises an odd number of main facets, in this case seven facets.

In a first step (FIG. 2A), seven edges 52 a-52 e are cut on the crown 4of the diamond. In the next stage (FIG. 2B), seven edges 54 a-54 e arecut on the base and a girdle is formed. FIG. 2C illustrates a compositeview of the stone showing both the top edges 52 a-52 e and the bottomedges 54 a-54 e.

In he following stages illustrated in FIGS. 2D and 2E, the stone is“brilliantized”, with the addition of facets 60 and half facets 62 tothe crown. FIG. 2E illustrates the addition of facets 56 and half facets58 to the base of the stone. The completed stone is shown in FIG. 2F andcomprises a substantially 7-pointed star shape.

A further embodiment of the “Galush” cut diamond is shown in FIGS. 3Aand 3B. FIG. 3A illustrates a stone 30 having a “French” culet, as isknown in the art, formed on the base of the stone. The facets extendingfrom the culet to the girdle may form a substantially four-pointed starshape 32. The crown may be “brilliantized” with facets and half facets,as previously illustrated, for example, in either FIGS. 1A-1F or FIGS.2A-2F.

FIG. 3B illustrates the formation of a plurality of facets 36(“brilliantizing”) on the base of a stone 34 (having a “Galush” shape)which appear to emanate from a common point 38. The plurality of facets36 form a triangular shape.

In another embodiment shown in FIG. 4, there is illustrated a “Galush”cut diamond, generally designated 40, having seven edges and a pluralityof facets. The finished stone comprises a seven-pointed star shape 42(similar to FIG. 2F).

In another embodiment of the “Galush” diamond, shown in FIGS. 5A-5C,there is illustrated a “Galush” cut diamond, generally designated 60,having a plurality of edges and/or stepped rhomboidal facets 62 formedon the base (FIG. 5A) and a plurality of edges and/or stepped rhomboidalfacets 64 formed on the crown (FIG. 5B). The complete diamond is shownin FIG. 5C.

It will be appreciated by persons knowledgeable in the art, that thedesign possibilities are limitless. It will also be appreciated bypersons knowledgeable in the art that variations may be made to the cutof a stone without detracting from the “Galush” cut of the invention.For example, the cut of the stone may be varied by the addition orsubtraction of facets and half facets. Furthermore, though the abovedescription relates to a diamond, it will be appreciated that a similarcut may be applied to other gemstones.

1. A gemstone comprising a crown portion, a pavilion portion and agirdle portion provided between the crown portion and pavilion portion,said crown portion comprising: an upper surface having a shapeconfigured by first, second and third boundaries, each of said first andsecond boundaries having a first and second ends, said third boundarybeing arc-shaped and having first and second edges; and wherein saidfirst and second edges of the arc-shaped boundary adjoin the first endof each of said first and second boundaries and wherein the second endof each of said first and second boundaries meet at a common tip,wherein said first, second and third boundaries form a perimeter aroundthe gemstone.
 2. The gemstone according to claim 1, wherein said crownportion further comprises: a plurality of facets formed from a pluralityedges, each edge adjoining two other edges around the perimeter.
 3. Thegemstone according to claim 2, wherein said plurality of edges is an oddnumber of edges.
 4. The gemstone according to claim 2, wherein saidplurality of facets comprises substantially rhomboidal facets.
 5. Thegemstone according to claim 2, wherein said crown portion furthercomprises a plurality of secondary star facets.
 6. The gemstoneaccording to claim 1, wherein said pavilion portion comprises aplurality of facets formed from a plurality edges, each edge having acommon end.
 7. The gemstone according to claim 6, wherein said pluralityof edges is an odd number of edges.
 8. The gemstone according to claim6, wherein said wherein said plurality of facets form a shape comprisingone of a group of shapes including a substantially five-pointed star ora seven-pointed star.
 9. The gemstone according to claim 6, wherein saidpavilion portion comprises substantially rhomboidal facets.
 10. Thegemstone according to claim 2, wherein said pavilion portion furthercomprises a culet base and a plurality of facets extending from theculet base to the girdle portion.
 11. The gemstone according to claim10, wherein said wherein said plurality of facets form a shapecomprising one of a group of shapes including a substantiallyfour-pointed star and a substantially triangular shape.
 12. A method forcutting a gemstone, said gemstone comprising a crown portion, a pavilionportion and a girdle portion provided between the crown portion andpavilion portion, the method comprising the steps of: configuring theperimeter of the crown of the gemstone in a shape comprising a surfacehaving first, second and third boundaries, each of the first and secondboundaries having a first and second ends, said third boundary beingarc-shaped having and having first and second edges; and wherein saidfirst and second edges of the arc-shaped boundary adjoin the first endof each of said first and second boundaries and wherein the second endof each of said first and second boundaries meet at a common tip, saidfirst, second and third boundaries forming the perimeter.
 13. The methodaccording to claim 12, further comprising the steps of: forming a firstplurality of edges on the crown of the gemstone, each of said firstplurality of edges adjoining two other of said first plurality of edges;and forming a second plurality of edges on the pavilion of the gemstone,each of said second plurality of edges adjoining two other of saidsecond plurality of edges.
 14. The method according to claim 13, whereinsaid first plurality of edges comprises an odd number of edges.
 15. Themethod according to claim 13, further comprising the step of forming aplurality of facets cut from said first plurality of edges.
 16. Themethod according to claim 15, further comprising the step of forming aplurality of secondary star facets.
 17. The method according to claim13, wherein said second plurality of edges comprises an odd number ofedges.
 18. The method according to claim 17, further comprising the stepof forming a plurality of facets cut from said second plurality ofedges, wherein each edge has a common end.
 19. The method according toclaim 18, wherein said wherein said plurality of facets form a shapecomprising one of a group of shapes including a substantiallyfive-pointed star or a seven-pointed star.
 20. The method according toclaim 18, wherein said plurality of facets comprise substantiallyrhomboidal facets.
 21. The method according to claim 13, wherein saidpavilion portion further comprises a culet base, the method furthercomprising the step of forming a plurality of facets extending from theculet base to the girdle portion.
 22. The method according to claim 21,wherein said plurality of star facets form a shape comprising one of agroup of shapes including a substantially four-pointed star and asubstantially triangular shape.